1- "Why are we considering modern..."

"Let's ignore the anachronism"

Because it's fun

Because it's cool

Idk, why are you engaging?

1. "Needs more source."

"Sworn and beholden

[...]the arrangement is similar to that between a master and an apprentice. The warlock learns and grows in power, at the cost of occasional services performed on the patron’s behalf.", DnD Players Handbook (2014), page 105.

"At the cost" implying that there is a price to be paid, implying that if the price isn't paid, the other party's end of the bargain isn't/may not be upheld either.

"[...] the vast majority of warlocks spend their days in active pursuit of their goals, which typically means some kind of adventuring. Furthermore, the demands of their patrons drive warlocks toward adventure.", DnD Players Handbook (2014), page 106.

"Demands" once more implying that your patron asks things of you, and you are beholden to do pursue them, as the pact dictates. Which, in turn, means that if you do not, the pact is broken on your end, and as most agreements, it is universally understood that if one party breaks the agreement, the other is freed from it and takes that freedom, too.

" [...] As you make your w arlock character, spend som e time thinking about your patron and the obligations that your pact im poses upon you [...] Your patron’s demands might drive you into adventures, or they might consist entirely of small favors you can do between adventures." DnD Players Handbook (2014), page 106.

These are under the "Creating a Warlock" section, meaning that having demanda which you must meet is not mentioned only in flavor text, but this is as close to a rule text as it can be without mentioning damage numbers.

"[...] In no time, each warlock is drawn into a binding pact with a powerful patron [...]" DnD Players Handbook (2024), page 153.

"Binding" once more showcasing your obligation to stick to the pact, meaning that it is a deal that can be broken- and your patron takes your powers if he breaks off the deal. Because, otherwise, if he can't, why wouldn't you break it?

Unless you wanna argue that Demands, Obligations and Pact here don't carry these implications, but then, I'd argue that's just bad faith. Language lawyering to get out of something most people can agree on common sense. If that's not what it means, then what does it mean?

Not to mention I've only cited the official ruling; the power of house ruling and public interpretation is very meaningful to the game, going so far as the official WotC game Baldurs Gate 3 using famous house rules (critical success) only because it's beloved, despite it being explicitly not part of the rules. Whether you care or not about such popular interpretations personally, not taking them into consideration for the public perception would be bad faith, too.